Heating system



' May 26, 1942.

s. R. PORWANCHER HEATING {SYSTEM Filed June 23, 1939 2 Sheets-Sheet l?Z/e/e for javzzlef$ olYuarzrlzeiz Patented May 26, 1942 HEATINGsxs'rlnvr Samuel R. Porwancher, Chicago, IlL, assignor to DryingSystems, 1110., Chicago,

tion'of Illinois 111., a corpora- Application June 23, 1939, Serial No.280,737 1 Claim. (01. 34-86) This invention relates .to heating systemsand. more particularly to reclaiming heat usually exhausted to theatmosphere or'otherwise dissipated without recovery in drying systems ofpaper making machines that employ air as the heat circulating medium.

In paper making machines, heated air is cir'- culated over the moistfibrous web to effect the desired drying or removal of moisturetherefrom, andthis air is thereafter exhausted to the atmosphere orotherwise dissipated without having the heat thereinextracted therefrom.The primary object of the present invention is to recover heat from theheated drying air passing from a paper making machine prior to theexhausting of such air, to the atmosphere or other dissipation thereof.7

Another object is to utilize heat recovered from the heated drying airfrom a paper making machine in any of a wide variety of ways.

A more specific object is to employ heat recovered from'the drying airpassing from a paper making machine to heat or assist in heating thebuilding in which the machine is housed or in the processing of the pulpfromwhichthe paper is produced.

Other objects and advantages of thepresent invention will be apparentfrom the following description wherein reference is made to theaccompanying drawings in which Fig. 1 is a transverse sectional viewtaken through a building in which a paper'making machine is housed, andwithwhich one form of my invention is associated; and

Fig. 2 is a horizontal sectional view of the building and apparatusshown in Fig. 1.

In the accompanying drawings I have shown' a paper making machine I 0,the details of which are unimportant for present purposes, and as isillustrated in Fig. 1 the machine is preferably mounted on a floor ll ofa building [2 above the lowest floor of such building.

through the upper portion of the hood. As herein'shown two exhaust orvent ducts l4 and M are provided at spaced points :along the top of thehood l3. (Fig. 2'). In the present instance each duct I4 and 14' opensinto an enlarged housing portion I5 and a'vent, stack l6 extends throughthe roof of the building l2 from each portion. [5. 'As shown in Fig. 1,each stack I 6 has draft inducing means, such as an exhaust ,fan ll,mounted therein and'such means is, in

the present "instance, driven by a belt l8 from a motor l9 mountedoutside of the stack. The fans operateto withdraw heated air from thezone of the machinethrough the hood l3, ducts. l4 and I4 and housingportions l5 and cause discharge of the air so withdrawn to theatmosphere through the stacks I6.

The air which is so circulated is heated by conventional air heatingmeans (not shown) and when drawn through the exhaust ducts l4 and hithis air still retains a large proportion of the heat which has thusbeen supplied, plus considerable moisture absorbed from the paper in thepaper making machine. In accordance with the present invention, the heatin this exhaust air is recovered in such a way as to be 'usable, eitherin the paper making processor for heating the building I! or for otherpurposes. To this end, each of the housing portions l5 has a heatexchanger mounted therein. Thus, as

' shown in Fig. '2, the portion It: in the passage 14 'In the operationof a machine of this type the ture-laden air withdrawn from the zone ofthe machine I0 is collected. The air flows from the hood t3 through aplurality of ducts opening has a coil 20 so mounted therein that the airdrawn through this housing must pass over the coillfl on its way to theexhaust stack l6 leadingfrom this housing. A similar coil 20iscorrespondingly mounted in the housing portion l5 in the duct l4.Preferably the coils 20 and 20' have radiating fins or plates'zl thereonso as to increase the efliciency thereof as heat transfer devices. p g VAheat circulating mediumysuch as water, is passed through the coils 20and 20 so that as the heated air from the zone of the ,machine flowsover the coils or heat exchangers 20 and 20' 'heat therefrom may betransferred to the medium circulated through the coils or heatexchangers. Heat so taken up by the medium circulated through the heatexchanges 20 and 20 is carried by the medium to other heat exchangers orthe like where such heat may be utilized.

As heatis extracted from the moisture-laden air by the coils 20 and 20,the temperature of the air usually drops slightly below its dew point,

whereby a film of moisture is deposited upon the coils. This is anadvantageous feature in that hence a more eflicient heat exchangearrangement is afforded. V

To this end the two heat exchangers or absorbing devices and 20' areincorporated in a fluid circulating system whichincludes a liquid supplytank 22 on the lower floor-23 of the builda ing 42, and by means of amotor driven pump 24,

liquid, which may be water,-from the tank is forced upwardly through ariser pipe 25 (Fig. 1 m V 29 and 29 to have heat picked up therebytransferred to other than intake air for the building 1) and thencethrough a branch pipe line 26' (Fig. 2) into one end of the'heatabsorbing can:

20 and through another branch pipe line2'l to;

'one end of the corresponding coil 20'. A pipe line 28 leads from theother end of the coil 2!! to a heat exchanger or transfer device 29which,

in the present instance, is positioned in an air intake duct 30 throughwhich fresh air is supplied to the interior of the building [2. As herein shown the intake duct 30 is connected toreceive airthrough a grilledopening 3| in a side wall 32 of the building I2, and is provided with anintakeblower 33 which is belt driven from a motor 34. Air drawn from theexterior ofthe building l2 throu'ghthe duct 30 is=discharged by-theblower 33 into a riserduct 35 from which it is' distributed about lthebuilding l2 through side discharge openings in connected overheaddistributing-ducts36. 1 I i The heat exchanger 29 is herein shown asbeing of the-same type as the exchangersn and 20and since 'w'ater heatedin the heat exchanger '20 .flows throughpipe line 28 to theheatexchanger the duct 30 having a blower 33 discharging through a riser 35'and overhead distributing ducts 36 disposed along side 32' of thebuilding. 3

The intake duct 3ll' is also provided with a 'heat exchange device 29,similar to the heat exchanger 29, and which is supplied with heatedwater from the heat exchanger 20' through a pipe line 28. fThis liquidis discharged intothe tank 22 by a return pipe line 31 which, as shownin Fig. 1, joins with the line 3 1 at 40. i By way of example, if airwithdrawn from'the zone of the machine It to flow through" the ex; haustductsld and HI and housing portions-l5 over the heat exchangers 20 and20"has a tem perature of from 170F. to 180 F.', sufficient heat may betaken therefrom in the heat exchangers 2n and 20' to reduce thetemperature of this'air to about 90 F.. before discharge of the airthrough the stacks IS. The heat so extracted from the air in the heatexchangers 20 and 20 is carried by the medium circulated through theseheat exchangers to the heat exchangers 29 and 29 where it may beutilized to heat fresh air taken in through the intake ducts 30 and 30'to a temperature of from F. to F. and this air I so heated is dischargedfrom the ducts 36 and 36' to heat theinteriorof the building I2.

, .Of course, the'pheat circulating medium flowing through the heatexchangers 20 and 20' could'be directed to means other than heatexchangers as l2. ,For example,.water heated in the heat ex changers!and 20' could be employed in the paper making process or be otherwiseutilized.

While Ihave illustrated and described a selected embodiment of myinvention, it is to be understood that this is capable of variation andmodification and I therefore do not wish to be limitedto theprecise'details set forth but desire to avail myself of such changes andalterations as fall the purview of the following claims m-' 3 7 a Thecombination with'a'building having side 'di uin' isicirculatedfor thepurpose of absorbing moisture-from paper material produced therein,

I a heat: reclaiming system c'omprising an exhaust hood overlying and fpartiallyjenclosing saidj machine,- an exhaust'passage leading from saidhood and communicating with the atmosphere outside the building, anexhaust fanin said passage for withdrawing heated air from the vicinityof the machine and discharging the same to atmosphere, a heat exchangerin said exhaust passage having coils through which a liquid may becirculated out of direct contact with the air flowing throughsaidpassage but in heat exchange relation'itherewith to absorb heattherefrom, there being an inlet passage in' one of the building sidewalls, a heat transfer device situated adjacent said inlet passage 'andremote 'from said heat ex-, changer and having coils through which a'liq uid may be circulated out of direct contact withair passed oversaid heat transfer device but in heat exchange relation; therewith totransfer heat thereto, means interconnecting the'coilsof said heatexchanger and said heat transfer device in a closed circulatory system,and pump' mea bodied in said system operable to circulate a liquidtherethro'ugh for'carrying "heat absorbed in said heat exchanger to saidheattransfer device, and a distributor duct communicating with the inletpassage and having a discharge outlet for air positioned adjacent theupper regions of the building and'remote from the paper making machineii 7 I SAMUELRPORWANCHER.

